Automatic choke for shotguns



Jan. 13, 1959 G. M. KEIGHTLEY AUTOMATIC CHOKE FOR SHOTGUNS 4 Sheets-Sheet 1 Filed Jan. 25, 1956 INVENTOR.

G. M. KEIGHTLEY Jan, 1959 G. M. KEIGHTLEY ,5 9

AUTOMATIC CHOKE FOR SHOTGUNS Filed Jan. 23, 1956 4 SheetsSheet 2 INVENTOR.

G. M. K EIGHTLEY Jan. 13, 1959 e. M. KElGHTLEY AUTOMATIC CHOKE FOR SHOTGUNS 4 Sheets-Sheet 4 Filed Jan. 23, 1956 FIG. /4

FIG. /6

INVENTOR. G.M. KEIGHTLEY ATTORNEY AUTOMATIC CHOKE FOR SHOTGUNS George M. Keightley, Wichita, Kans., assignor to Jarvis Manufacturing, Inc., Wichita, Kans., a corporation of Kansas Application January 23, 1956, Serial No. 560,493

Claims. (Cl. 42-79) This invention relates to firearms. In a more specific aspect, this invention relates to shotguns. In a still more specific aspect, this invention relates to choke apparatus for shotguns. In yet a more specific aspect, this invention relates to automatic choke apparatus for shotguns whereby the choke of the gun automatically goes from open barrel to modified choke to a full choke position on successive firings of the gun.

Shotgun choke devices have long been known in the art. These devices are mounted on the outer end of the barrel and such are used to restrict the cross sectional area of the outer end portion of the resulting barrel, so that when the gun is fired the shot pattern resulting will be smaller at a given distance or'the same effective shot pattern can be maintained at a greater distance. Choke apparatus is known in the art which mechanically restricts the outer end portion of the gun barrel at one or more positions, and it is known to use the gases of explosion resulting from firing the gun to actuate mechanism to automatically restrict the barrel at one or more positions. Some of the latter mechanisms utilize thrustresulting from passing some explosion gases from the barrel through a restricted opening, and others utilize the gases to disengage means to allow other mechanism to automatically restrict the outer end portion of the barrel resulting from mounting the choke apparatus thereon. All of the automatic choke devices of the prior art have their disadvantages. They are either not practical or are not reliable. I have invented new automatic choke apparatus, and my new choke structure has proven itself to be far superior to that of the prior art in actual use.

The new choke apparatus for a shotgun of my invention has a first body member portion which in use is attached to the outer end portion of the barrel of the shotgun and extends the barrel. This body member has a contractile section which is restricted to reduce its cross sectional area. In the new choke structure of my invention, there are two operating members, and one of these is movably mounted on the first or front body member so that it is operable as it moves to vary the cross sectional area of the contractile section. A second body member portion is used and it is mounted on the barrel preferably to the rear of and spaced from the first body member portion. The other operating member of my new choke structure is movably mounted in relation to the second or rear body member portion and the first operating member, and it is operable as it moves to move the first operating member and thus vary the cross sectional area of the contractile section. Means are operatively connected to the second or linking operating member to continuously urge same to move, to in turn move the front or first operating member and in turn restrict the contractile section of the front or first body member. A latch is mounted for latching operation on the second or rear body member portion, and the second or linking operating member has means in its rear portion to receive the latch member to hold this atent 2,867,932 Patented Jan. 13, 1959 second operating member against movement thus preventing the first operating member from varying the cross sectional area of the contractile section of the first or front body member portion. The new choke apparatus of my invention has means which yieldably holds the latch in engagement to prevent the linking operating member from moving, and has means which is connected to this apparatus and which is adapted to momentarily disengage the latch at each successive firing of the shotgun to allow for movement of the operating members to restrict the contractile section.

It is an object of this invention to provide new firearm means.

It is another object of this invention to provide new shotgun means.

Still another object of this invention is to provide new choke apparatus for shotguns.

Yet another object of this invention is to provide new choke apparatus for shotguns which will automatically and reliably upon firing the gun change the barrel outlet from a first shot open barrel, to a second shot modified choke or restricted barrel outlet, to a full choke or fully restricted barrel outlet.

Other objects and advantages of the new choke apparatus of my invention will become apparent to those skilled in the art upon reading this disclosure.

Drawings accompany and are a part of this disclosure. These drawings depict preferred specific embodiments of the new choke apparatus of my invention, and it is to be understood that such are not to unduly limit the scope of my invention.

In the drawings, Fig. 1 is a longitudinal view partly in cross section and partly cut away showing a preferred specific embodiment of the new choke means of my invention mounted on a shotgun barrel.

Fig. 2 is a perspective view of the front operating sleeve thereof.

Fig. 3 is a perspective view of the front body member having the contractile section.

Fig. 4 is a perspective view of the linking operating sleeve of the choke device.

Fig. 5 is a perspective view of the operating spring of the device.

Fig. 6 is a perspective view of the rear body member which carries the latch for the choke device.

Fig. 7 is a perspective view of the rear operating sleeve of the device which carries the means which the latch engages to lock the choke against operation.

Fig. 8 is a perspective view of the latch member.

Fig. 9 is a perspective view of the rear locking member of the device which is used to lock the choke in open or modified choke or to actuate the mechanism to move it to full choke position Without firing the gun.

Fig. 10 is a perspective view of the outer sleeve member which is used to operate the locking member.

Fig. 11 is a longitudinal view partly in cross section and partly cut away showing another preferred specific embodiment of the choke means of my invention wherein the gun barrel is choked upon the front operating sleeve sliding forwardly on the body member having the contractile section, which is the reverse of the operation of the embodiment of Fig. 1.

Fig. 12 is a perspective view of the front operating sleeve of this embodiment.

Fig. 13 is a perspective view of the front body member of this embodiment having the contractile section.

Fig. 14 is a perspective view partly in outline and partly cut away of another. preferred embodiment of latching means for the choke device which utilizes the shotgun recoil upon firing and the inertia of a freely movable Weighting member.

Fig. 15 is a longitudinal elevation view partly in cross barrel 18 between same and linking sleeve 34.

section'showing the latching assembly for this latch operating means.

Fig. 16 is a perspective View of another preferred embodiment of latching means for the choke device which utilizes a piston pressure by explosion gases upon firing the shotgun to unlatch the assembly of Fig. 15.

Following is a discussion and description of the new choke apparatus of my'invention made with reference to the drawings whereon the same reference numerals are used to indicate the same parts and/or structure. The discussion and description are of preferred specific embodiments, and it is to be understood that such are not to unduly limit the scope of my invention. Referring now to Figs. 1 through 10, the choke device is mounted on the outer end of the gun barrel 18 which can be threaded as shown to receive and mount the front body member 20, or as in many instances a sleeve member (not shown) can be soldered or welded to the barrel 18 to receive the front body member either threadedly, or welded or soldered thereto. I have found such a sleeve desirable to not only strengthen the barrel but to act to properly position and align the choke parts, particularly the rear body member in relation to front body member 20. This body member has a contractile section formed by cutting longitudinal grooves 22 therein, so that the cross sectional area of the contractile section can be reduced to choke the gun barrel.

This restriction of the contractile section is accomplished by operating sleeve 24 which is slidably mounted on body member 20. Sleeve 24 preferably has an inwardly projecting circumferential raised portion 26 about its outer end which contacts the contractile section and as sleeve 24 moves rearwardly it restricts the diameter of the contractile section more and more. The position shown in Fig. 1 is that of full choke. When full open, portion 26 is preferably out over the outer end of the contractile section, and when in modified choke a position intermediate these is maintained. Sleeve 24 is slidably mounted on body member 20 by pins 28 rigidly mounted in holes 30 in sleeve 24, such pins projecting into slots 32 which are diametrically formed in body member 20. Sleeve 24 then can slide back and forth on member 20 but cannot turn in relation to member 20.

A linking sleeve member 34 is desirably used and such is operatively connected to turn in relation to sleeve member 24 by threaded connection 36. When sleeve member 34 is turned in operation, restricting sleeve 24 slides on body member 20 to vary the diameter of the contractile section thereof. Sleeve 34 is preferably knurled, since this sleeve is held for turning to reset the automatic choke device.

An operating sleeve member 38 is likewise concentrically mounted around barrel 18 as are sleeves 24 and 34; and this sleeve 38 is threadedly secured and pinned (pin screws not shown) to sleeve 34 by assembly threads 40. Sleeve 38 in operation turns with sleeve 34, and this operating sleeve member 38 is the member which is held by the latch means of the device to prevent sliding of member 24 to vary the cross sectional area of the contractile section.

. A spiral spring 42 is concentrically mounted around This spring acts in torsion and furnishes the force for operating the choke device. It is rigidly attached to body member 20 in its front end by any suitable means, such as by welding or soldering, and is attached to sleeve member 38 by end portion 44 inserted in hole 45. A pin (not shown) through hole 49' in sleeve 38 retains spring end 44 in hole 45. Spring 42 continuously urges sleeve member 38 to turn and thus through sleeves 34 and 24 the contractile section of body member 20 is continuously urged into a contracted position.

Sleeve 38 is threadedly mounted around and secured to rear body member 46 by operating threads 48. Body member .46 is rigidly secured concentrically to barrel 18 or to a sleeve member mounted on barrel 18, as discussed hereinbefore. Threads 48are the reverse of the other operating threads 36, :that is, one set is right-handed and the other left-handed, and in the embodiment of Fig. l, the threads 36 are right-handed while the threads 48 are left-handed, so that when operating sleeve 38 turns under the force 0f-"sprin'g'42 in a counterclockwise direction while sighting the gun normally, and sleeve 34 therewith, operating sleeve 24 is moved rearwardly to contract the contractile section of member 20.

Rear or latch body 46-is slotted at 50 to receive latch member 52 which is pivotally mounted therein by pin 54 in its middle portion, pin 54 being anchored in the walls of member 46 by any suitable means. The forward end portion 56 of latch member 52in operation catches sleeve member 38 to prevent its turning by engaging it in one of the angularly spaced notches 58. A spring 60 mounted in circumferential groove 62 and the corresponding groove 64 in latch 52 bears against end portion 66 of member 52 to urge the latch into latching engagement with one of the notches 58 of sleeve 38, as shown in Fig. l. A hole 68 is drilled in barrel 18 into communication with the interior thereof, and end portion 66 of latch 52 covers this hole in normal position. To prevent corrosion of the metal latch member as a result of the hot gases of explosion contacting the latch, I prefer to employ a non corrosive plug member 70 which fits into hole 68 and contacts latch 52 in a recess therein. When the shotgun is fired explosion gases through hole 68 exert force on plug 70 and thus latch member 52, to momentarily pivot same against the force of spring 60, end portion 56 thereof moving substantially radially inwardly to disengage the latch and release sleeve member 38 for turning to in turn restrict the contractile section of member- 28. When the pressure inside barrel 18 drops back after the shot is fired, spring 60 pivots latch 52 and end portion 56 is moved substantially radially outwardly and into the path of the next notch 58 wherein'it latches to prevent further turning of sleeve 38 by spring 42. Thus, starting with the contractile section of member 20 full open, and latch 52 in the full open notch, the first shot of the gun will momentarily release sleeve 38 to turn to the modified choke notch where latch 52 will engage modified notch 58 and hold in this position for the second shot. The second shot of the gun will then release sleeve 38 to turn to the full choke notch where latch 52 catches sleeve 38 again in full choke position. In each instance operating sleeve 24 is slid back on member 20 as a result of sleeves 38 and 34 turning together to shorten the distance between sleeve 24 and latch body member 46.

So as to reset the choke device for further automatic choking by backwardly turning preferably knurled sleeve 34, the rearward face of each of the notches 58 is preferably inclined inwardly (Fig. 7) to form a cam surface and the contacting corner 72 of latch 52 is beveled (Fig. 8). The cam surfaces upon the backward turning of sleeve 38 push latch portion 56 inwardly against the force of spring 60 so that the notches 58 pass over the latch member 52 until the latch falls into the full open barrel notch 58. The rearward face of notches 58 is considered to be the face opposite the leading edge of the notch when sleeve 38 is being turned on member 46 by spring 42.

Stop dogs 74 projecting rearwardly from sleeve 38 are provided, along with dog 76 on member 46, to limit the travel of sleeve 38. In turning in either direction dog 76 will contact the respective dog 74 to limit travel of sleeve 38. This is preferable so that when full choke position is reached, the mechanism will not act to further contract the contractile section of member 20. Likewise, when re setting the mechanism the dogs will prevent forward movement of sleeve 24 past full open position of the gun barrel.

A locking member 78 and a preferably knurled assembly sleeve 80 therefore is desirably provided so that the choke apparatus can be locked in full open position, or so that it can be moved to full choke position without firing the gun. In certain instances the hunter or sport shooter wants to maintain the shotgun in full open position for all shots, or he wants to maintain the gun in full choke position for all shots. Locking sleeve 78 is a splitring type with spaced circumferential projecting portions 82 and 84, and it is concentrically mounted around latch body member 46. Ring member 78 is split enough so that latch member 52 can pivot between portions 82 and 84 when ring 78 is in normal operating position for the choke apparatus to operate automatically. If it is desired to lock the choke apparatus in a particular position, sleeve 78 is turned until one of the portions 82 and 84 contact latch member 52 to Prevent its pivoting. Figs. 1 and 11 show sleeve 78 in position with portion 84 over end portion 66 of the latch member 52 so that the latch is engaged to prevent the choke apparatus from operating. When sleeve 78 is turned in the opposite direction, portion 82 of sleeve 78 covers portion 56 of latch 52 to disengage same so that the choke will automatically act to fully restrict the contractile section of body member 20. A transverse groove 86 is provided in latch body 46, and the inner end of assembly screw 88 through sleeve 80 and ring 78 rides in this groove 86 to limit travel of member 78. The screw 88 also connects sleeves 78 and 80 together so that they move together when sleeve 80 is turned by hand.

In Figs. 11, 12 and 13 is shown another preferred embodiment of the new choke means of my invention wherein the front operating sleeve 90 restricts the contractile section of body member 92 upon sliding forwardly in relation thereto and the reverse of sleeve 24 in the embodiment of Fig. l. Member 92, as member 20, is preferably threadedly mounted on barrel 18, or on a sleeve threadedly or Weldedly secured to barrel 18. Elongated notches 22 in member 92 provide for the contractile section, and pins 28 riding in grooves 32 in body member 92 prevent rotation of members 90 and 92 in relation to each other. In this instance threads 36 and 48 are reversed from their direction in the embodiment of Fig. 1, so that upon the turning of sleeve members 34 and 38 by spring 42, the distance between latch body member 46 and operating sleeve 90 is increased. Thus, when the gun is fired, latch member 52 from gas pressure through hole 68 is pivoted to release portion 56 from engagement with operating sleeve notches 58. Sleeve 34 is then turned through spring 42 to move sleeve 90 forward to place the contractile section of member 92 in a more restricted position.

In Figs. 14 and 15 is shown another preferred latching means which operates on the inertia of weighting members against movement, upon shooting the gun and it recoiling as a result thereof. Latch member 52 in this instance has a slot 94 therethrough. A linking arm 96 rides in this slot 94, and it projects out through each side of the latch housing. Weighting members 98 are attached one to each end of arm 96, and these weighting members are housed in cylindrical members 100 mounted by posts 102 on the outside of the choke apparatus. Arm 96 moves back and forth in a slot 104 in housing 100, and weighting members 98 move freely in relation to housing 100 except as limited by spiral springs 106. This latch apparatus works as follows: When the gun is fired, the barrel 18 and choke apparatus proper recoil to move rearwardly, including latch 52 and sleeve 38. The inertia of weighting members 98 and arm 96 which are freely mounted cause them to momentarily remain stationary. They are of sufficient mass to overcome the frictional drag of the surfaces of slot 94 on arm 96. Because of the curvature of slot 94, latch 52 moving in relation to arm 96 will be pivoted, releasing portion 56 from engagement with rotatable sleeve 38 and allowing the choke apparatus to choke'the shotgun. Springs 106 act to cushion weights 98 when full travel of arm 96 in slot 94 has occurred. Also, they act to reposition latch 52 and weights 98 to which they are preferably attached so that the apparatus can function further to choke the gun. In this respect spring member 60 continuously urges latch 52 into engagement, and reengagement occurs after shooting so that the choke means is held in modified choke position, for example, until a subsequent shot again releases the latch from engagement.

In Figs. 15 and 16 is shown another preferred latching means which operates on the gas pressure of the explosion gases resulting from firing the shotgun. In this means a cylinder 108, having a piston 110 and rod 112 mounted therein, is attached to the choke apparatus housing in any suitable manner. A conduit 114 communicates with the cylinder head chamber and the interior of barrel 18. Piston rod 112 has an arm member 116 attached thereto in any suitable manner and moves therewith. This arm 116 mounts arm 96 which rides in the curved slot 94 in latch member 52. A fixed partition wall 118 supports spring 120 which is attached thereto in one end, the other end of spring 120 being attached to rod 112, arm 116 and arm 96. As a result latch 52 is operates as follows: When the gun is fired explosion gases from barrel 18 pass into the head chamber of the cylinder and force piston 110 forward, and thus piston rod 112, arm 116 and arm 96. A s a result latch 52 is pivoted, disengaging portion 56 thereof from sleeve 38 and notches 58 therein, thereby allowing the choke apparatus to react to choke the gun. When the gas pressure drops after firing, spring 120 returns rod 112 and piston 110 to normal position, and along with spring 60 pivots latch member 52 so that portion 56 thereof can reengage sleeve 38.

As will be evident to those skilled in the art, various modifications of this invention can be made, or followed, in the light of this disclosure and discussion, Without departing from the spirit or scope of the disclosure or from the scope of the claims.

I claim: I

1. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, said second body member having a stop dog extending radially therefrom, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member-and said second body member and operable as it is turned on said second body member to slide said first sleeve member, a pair of stop dogs angularly mounted on said second sleeve member and extending rearwardly therefrom, one of said dogs on said second sleeve member being positioned and operative on turning said second sleeve member to engage said dog on said second body member to limit travel of said second sleeve member in one direction and the other of said dogs on said second sleeve member being positioned and operative upon turning said second sleeve member to engage said dog on said second body member to limit travel of said second sleeve member in the other direction, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a plurality of angularly spaced notches in said second sleeve member, a latch member mounted on said second body member and operable to catch said second sleeve member with said latch member in engagement in one of said notches, an opening through said barrel communicating with the interior of said barrel, and means mounted on said second body member yieldably urging said latch member to cover said opening'and into latching engagement with said second sleeve member, said latch member, being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member.

2. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a plurality of angularly spaced notches in said second sleeve member, the rearward face of each of said notches being inclined inwardly to form a cam surface whereby said second sleeve member can be turned rearwardly to reset same, said rearward face of said notches being considered the one opposite the leading edge of said notches when said second sleeve member is being turned by said means to turn same on said second body member, a latch member mounted on said second body member and operable to catch the second sleeve member with said latch member in engagement in one of said notches, said cams urging said latch member out of latching engagement to permit said notches to pass over said latch member, an opening through said barrel communicating with the interior of. said barrel, and means mounted on said second body member yieldably urging said latch member to cover said opening and into latching engagement with said second sleeve member, said latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member.

3. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a plurality of angularly spaced notches in said second sleeve member,

a latch member mounted on said second body member and operable to catch said second sleeve member with said latch member in engagement in one of said notches, an opening through. said barrel communicating with the interior of said barrel, means mounted on said second body member yieldably urging said latch member to cover said opening and into latching engagement with said second sleeve member, said latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latchmemberand allow 8 turning of said second sleeve member, and a split-ring sleeve member limitably and rotatably disposable concentrically about said second body member, said splitring sleeve havingarmmeans operative to lock said latch member in engaged position and in disengaged position, as desired.

4. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said'second body member and operable'as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a plurality of angularly spaced notches in said second sleeve member, a latch member mounted on said second body member and operable to catch said second sleeve member with said latch member in engagement in one of said notches, an opening through said barrel communicating with the interior of said barrel, and means mounted on said second body member yieldably urging said latch member to cover said opening and into latching engagement with said second sleeve member, said latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member, and stop means with said second sleeve member and said second body member to limit the travel of said second sleeve member in either direction, and the rearward face of each of said notches in said second sleeve member being inclined inwardly to form a cam surface.

5. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the crosssectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a plurality of angularly spaced notches in said second sleeve member, a latch member mounted on said second body member and operable to catch said second sleeve member with said latch member in engagement in one of said notches, an opening through said barrel communicating with the interior of said barrel, means mounted on said second body member yieldably urging said latch member to cover said opening and into latching engagement with said second sleeve member, said latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member, engageable stop means with said second sleeve member and said second body mem ber to limit travel of said second sleeve member in both directions, the rearward face of each of said notches in said second sleeve member being inclined inwardly to form a cam surface, and means mounted on said second body member which are constructed and operable to lock said latch member in engagement and in disengagement, as desired.

6. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said firstbody member, a second sleeve member disposable concentrically about said barrel, movably and threadedly connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, a spiral spring concentrically disposable about said barrel and between same and said second sleeve member, said spring having one of its end portions connected to said first body member, the other of its end portions connected to said second sleeve member and acting in torsion to urge said second sleeve member to turn, a plurality of angularly spaced notches in said second sleeve member, an opening through said barrel communicating with the interior of said barrel, a latch member comprising an elongated bar-like member pivotally mounted in its middle portion on said second body member, the rear portion of said member being in contact with a loose plug in said opening to urge said plug to close said opening and the forward portion of said latch member being operative to engage said notches to latch, a spring mounted in a circumferential groove in said second body member corresponding with a groove in the rear end portion of said latch member, said lastnamed spring urging said latch member to cover said opening and into latching engagement, the rearward face of each of said notches is inclined inwardly to form a cam surface, whereby said second sleeve member can be turned rearwardly to reset same with said cams urging said latch member out of latching engagement to permit said notches to pass said latch member, a pair of stop dogs angularly mounted on said second sleeve member and extending rearwardly therefrom, a stop dog on said second body member and extending radially therefrom, one of said dogs on said second sleeve member being positioned and operative upon turning said second sleeve member to engage said dog on said second body member to limit travel of said second sleeve member in one direction and the other of said dogs on said second sleeve member being positioned and operative upon turning said second sleeve member to engage said dog on said second body member to limit travel of said second sleeve member in the other direction, and a split-ring sleeve member limitably and rotatably disposable concentrically about said second body member, said split-ring sleeve member having arm members operative to lock said latch member in engaged position and in disengaged position, as desired, to maintain said first sleeve member in fixed position relative to said first body member irrespective of the firing of said shotgun, and said latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member.

7. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposed about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a latch member mounted on said second body member, said second sleeve member having catch means in its rear portion to receive said latch member to latch said second sleeve member against turning on said second body member, said apparatus having means yieldably holding said latch member in engagement to prevent movement of said second operating member, and an opening through said barrel oommunicating with the interior of said barrel and an expansion chamber having a movable piston-like member which moves upon expansion of said chamber, said piston-like member being operatively connectable to said latch member, and said piston-like member being operable to disengage said latch member as a result of gas pressure being exerted on said piston-like member through said opening upon said firing of said shotgun.

8. Choke apparatus for a shotgun, comprising, in combination, a first body member mountable on the barrel of said shotgun to form an extension thereof and having a contractile section, a first sleeve member disposable concentrically about said first body member and in slidable relation thereto and operable as it is slid on said body member in one direction to restrict said contractile section to reduce the cross sectional area thereof, a second body member concentrically disposable about and securable to said barrel and spaced from said first body member, a second sleeve member disposable concentrically about said barrel, movably connected to said first sleeve member and said second body member and operable as it is turned on said second body member to slide said first sleeve member, resilient means operatively connectable to continuously urge said second sleeve member to turn on said second body member, a latch member mounted on said second body member, said second sleeve member having catch means in its rear portion to receive said latch member to latch said second sleeve member against turning on said second body member, said apparatus having means yieldably holding said latch member in engagement to prevent movement of said second operating member, and a weighting member which is operatively connectable to said latch member, said weighting member being mounted to move free in relation to said apparatus upon recoil of said shotgun due to the inertia of said weighting member, said weighting member operative to disengage said latch member upon firing said shotgun.

9. Choke apparatus for a shotgun comprising, in combination, a body assembly having a forward portion and mountable on the barrel of said shotgun to form an extension thereof, said forward portion having a contractile section, a first sleeve member disposable concentrically about said forward portion and in slidable relation thereto and operable as it is slid on said forward portion in one direction to restrict said contractile section to reduce the cross sectional area thereof, a rearward portion of said body assembly spaced from said forward portion when said choke apparatus is mounted on said shotgun,

said rearward portion having a stop dog extending radially therefrom, a second sleeve member disposable concentrically of said forward and rearward portions and the longi- 11 onsaid secondsleevemember being positioned and operative on turning said second' sleeve member to engage said dog on said rearward portionto limit travel of said second sleeve ,in'onevdirection andvthe other of said dogs on said second sleeve member being'positioned and operative upon turning said second sleeve member to engage said dog on said rearward portion to limit travel of said second sleeve member in the other direction, a spiral spring concentrically mounted about said forward portion and rearward portion and said longitudinal axis of said shotgun barrel, said spring mounted between said forward and rearward'portions and operatively connected to continuously urge said second sleeve member to turn on said rearward portion, a plurality of angularly spaced notches in said second sleeve member, a latch member mounted on said rearward portion and operable to catch said second sleeve member with said latch member in engagement in one of said notches therein, an opening through said rearward portion communicating with the interior of said barrel of said shotgun, and means mounted on said rearward portion yieldably urging said latch member to cover said opening and into latching engagement T2 with said second sleevemembensaid latch member being disengageable by gas pressure on said latch member exerted through said opening upon shooting said gun to allow one of said notches to pass said latch member and allow turning of said second sleeve member.

10. The choke apparatus of claim 9 wherein a splitring sleeve member is limitably and rotatably disposed concentrically about said rearward portion of said body assembly and said split-ring sleeve has arm means operatively engageable with said latch member to lock same in engaged position and in disengaged position, as desired, and said second sleeve member and said rearward portion have stop means to limit travel of said second sleeve member in both directions.

References Cited in the file of this patent UNITED STATES PATENTS 2,676,429 Gotterson Apr. 27, 1954 2,759,286 Moore Aug. 21, 1956 2,765,564 Schroeder Oct. 9, 1956 2,779,119 Fawcett Jan. 29, 1957 

